Subatomic Physics Chapter 25-1. Properties of the Nucleus The nucleus is the small, dense core of an...
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Transcript of Subatomic Physics Chapter 25-1. Properties of the Nucleus The nucleus is the small, dense core of an...
Properties of the NucleusProperties of the NucleusThe nucleus is
the small, dense core of an atom.
Atoms that have the same atomic number but different neutron numbers are called isotopes.
Properties of the Nucleus Properties of the Nucleus A particle has a certain amount
of energy (rest energy) associated with its mass.
Nuclear StabilityNuclear Stability
The nucleus of an atom is able to exist because of a nuclear force called a strong force.
Strong force is the attractive force between the protons and neutrons.
Binding EnergyBinding EnergyEnergy involved when
components of a nucleus are forced together or split (fusion/fission).
Nuclear Decay Nuclear Decay Nuclear decay
can happen in nature or induced artificially.
When a nucleus decays radiation is emitted as particles, photons or both.
Measuring Nuclear DecayMeasuring Nuclear DecayThe decay
constant indicates the rate of radioactive decay.
Half-life measures how long it takes half a sample to decay
Nuclear ReactionsNuclear ReactionsA change in the nucleus of an
atom is called a nuclear reaction.
Fission – a nucleus splits into two or more nuclei.
Fusion – one or more nuclei combine.
Nuclear BombNuclear BombIf a chain
reaction happens too fast, it could result in a violent explosion.
This is the principle behind the first nuclear bomb.
Nuclear ReactorsNuclear ReactorsA nuclear reactor
is a system designed to maintain controlled self sustained chain reactions.
All nuclear reactors operate through fission.
Fusion occurs naturally only for light atoms.
Four Fundamental Four Fundamental InteractionsInteractionsAll particles in nature are subject to four fundamental interactions :
Strong – “glue” that holds nucleons together ; strongest
Electromagnetic – attraction of unlike and repulsion of like charges.
Weak – beta decay
Gravitational – holds planets, stars, and galaxies together; weakest
Classification of ParticlesClassification of ParticlesElectrons and
neutrinos are leptons.
Protons and neutrons are baryons.